A two-year study of these rocks in the Winchester area is being conducted to better understand how the dolomite zones formed, said Jim Drahovzal, head of the KGS energy and minerals section. “The results of this research will help companies locate oil and gas reservoirs deep within the subsurface, not only in the Appalachian Basin, but also across the eastern United States,” Drahovzal said.

Jan. 27, 2003 (Lexington, Ky.) -- Geologists and geophysicists from the Kentucky Geological Survey (KGS) at the University of Kentucky are conducting research along Ky. 627 in Clark County to help oil and gas companies investigate the potential for finding natural gas reservoirs.

“We’re partnering with a gas exploration company, Triana Energy of Charleston, W. Va., to examine geologic features in Central Kentucky to better understand how natural gas reservoirs form in the eastern United States,” said Dave Harris, a KGS petroleum geologist.

Harris said several localities in Clark County have unusual structures that indicate Ordovician age limestone (rock that is 440 to 470 million years old) had been converted to dolomite near faults and fractures. Hot fluids moving upward from deeper sources in the subsurface formed these unusual structures.

This process, which geologists refer to as “fault-controlled dolomitization,” has resulted in the formation of prolific oil and gas reservoirs elsewhere in the Appalachian Basin in Kentucky, Michigan, New York, Ohio and Ontario, Canada, where the same rocks are buried 5,000 to 8,000 feet deep. Unlike the host limestone, dolomite commonly has excellent pore space, where natural gas and oil can accumulate.

A two-year study of these rocks in the Winchester area is being conducted to better understand how the dolomite zones formed, said Jim Drahovzal, head of the KGS energy and minerals section. “The results of this research will help companies locate oil and gas reservoirs deep within the subsurface, not only in the Appalachian Basin, but also across the eastern United States,” Drahovzal said.

The Clark County work will be done in two phases. The first phase, which is already under way, involves sampling limestone and dolomite in various locations. Laboratory analyses will then be done on the samples to determine the origin of the dolomite. The second phase will involve the acquisition of seismic and ground-penetrating radar profiles across the dolomite bodies, which will give geologists images of the shape of the dolomite in the shallow subsurface that they can relate to similar rock deeper in the subsurface.

After obtaining an idea of what the dolomite look like below the surface, they will drill two boreholes through the dolomite. Core samples of the rock from the boreholes will be collected for additional study.

The New York Energy Research and Development Authority, Triana Energy, the U.S. Department of Energy, and KGS are funding the study.